.\"	$OpenBSD: PKCS7_new.3,v 1.6 2019/06/10 09:49:48 schwarze Exp $
.\"
.\" Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: June 10 2019 $
.Dt PKCS7_NEW 3
.Os
.Sh NAME
.Nm PKCS7_new ,
.Nm PKCS7_free ,
.Nm PKCS7_SIGNED_new ,
.Nm PKCS7_SIGNED_free ,
.Nm PKCS7_ENVELOPE_new ,
.Nm PKCS7_ENVELOPE_free ,
.Nm PKCS7_SIGN_ENVELOPE_new ,
.Nm PKCS7_SIGN_ENVELOPE_free ,
.Nm PKCS7_DIGEST_new ,
.Nm PKCS7_DIGEST_free ,
.Nm PKCS7_ENCRYPT_new ,
.Nm PKCS7_ENCRYPT_free ,
.Nm PKCS7_ENC_CONTENT_new ,
.Nm PKCS7_ENC_CONTENT_free ,
.Nm PKCS7_SIGNER_INFO_new ,
.Nm PKCS7_SIGNER_INFO_free ,
.Nm PKCS7_RECIP_INFO_new ,
.Nm PKCS7_RECIP_INFO_free ,
.Nm PKCS7_ISSUER_AND_SERIAL_new ,
.Nm PKCS7_ISSUER_AND_SERIAL_free
.Nd PKCS#7 data structures
.Sh SYNOPSIS
.In openssl/pkcs7.h
.Ft PKCS7 *
.Fn PKCS7_new void
.Ft void
.Fn PKCS7_free "PKCS7 *p7"
.Ft PKCS7_SIGNED *
.Fn PKCS7_SIGNED_new void
.Ft void
.Fn PKCS7_SIGNED_free "PKCS7_SIGNED *signed"
.Ft PKCS7_ENVELOPE *
.Fn PKCS7_ENVELOPE_new void
.Ft void
.Fn PKCS7_ENVELOPE_free "PKCS7_ENVELOPE *envelope"
.Ft PKCS7_SIGN_ENVELOPE *
.Fn PKCS7_SIGN_ENVELOPE_new void
.Ft void
.Fn PKCS7_SIGN_ENVELOPE_free "PKCS7_SIGN_ENVELOPE *signed_envelope"
.Ft PKCS7_DIGEST *
.Fn PKCS7_DIGEST_new void
.Ft void
.Fn PKCS7_DIGEST_free "PKCS7_DIGEST *digested"
.Ft PKCS7_ENCRYPT *
.Fn PKCS7_ENCRYPT_new void
.Ft void
.Fn PKCS7_ENCRYPT_free "PKCS7_ENCRYPT *encrypted"
.Ft PKCS7_ENC_CONTENT *
.Fn PKCS7_ENC_CONTENT_new void
.Ft void
.Fn PKCS7_ENC_CONTENT_free "PKCS7_ENC_CONTENT *content"
.Ft PKCS7_SIGNER_INFO *
.Fn PKCS7_SIGNER_INFO_new void
.Ft void
.Fn PKCS7_SIGNER_INFO_free "PKCS7_SIGNER_INFO *signer"
.Ft PKCS7_RECIP_INFO *
.Fn PKCS7_RECIP_INFO_new void
.Ft void
.Fn PKCS7_RECIP_INFO_free "PKCS7_RECIP_INFO *recip"
.Ft PKCS7_ISSUER_AND_SERIAL *
.Fn PKCS7_ISSUER_AND_SERIAL_new void
.Ft void
.Fn PKCS7_ISSUER_AND_SERIAL_free "PKCS7_ISSUER_AND_SERIAL *cert"
.Sh DESCRIPTION
PKCS#7 is an ASN.1-based format for transmitting data that has
cryptography applied to it, in particular signed and encrypted data.
.Pp
.Fn PKCS7_new
allocates and initializes an empty
.Vt PKCS7
object, representing an ASN.1
.Vt ContentInfo
structure defined in RFC 2315 section 7.
It is the top-level data structure able to hold any kind of content
that can be transmitted using PKCS#7.
It can be used recursively in
.Vt PKCS7_SIGNED
and
.Vt PKCS7_DIGEST
objects.
.Fn PKCS7_free
frees
.Fa p7 .
.Pp
.Fn PKCS7_SIGNED_new
allocates and initializes an empty
.Vt PKCS7_SIGNED
object, representing an ASN.1
.Vt SignedData
structure defined in RFC 2315 section 9.
It can be used inside
.Vt PKCS7
objects and holds any kind of content together with signatures by
zero or more signers and information about the signing algorithm
and certificates used.
.Fn PKCS7_SIGNED_free
frees
.Fa signed .
.Pp
.Fn PKCS7_ENVELOPE_new
allocates and initializes an empty
.Vt PKCS7_ENVELOPE
object, representing an ASN.1
.Vt EnvelopedData
structure defined in RFC 2315 section 10.
It can be used inside
.Vt PKCS7
objects and holds any kind of encrypted content together with
content-encryption keys for one or more recipients.
.Fn PKCS7_ENVELOPE_free
frees
.Fa envelope .
.Pp
.Fn PKCS7_SIGN_ENVELOPE_new
allocates and initializes an empty
.Vt PKCS7_SIGN_ENVELOPE
object, representing an ASN.1
.Vt SignedAndEnvelopedData
structure defined in RFC 2315 section 11.
It can be used inside
.Vt PKCS7
objects and holds any kind of encrypted content together with
signatures by one or more signers, information about the signing
algorithm and certificates used, and content-encryption keys for
one or more recipients.
.Fn PKCS7_SIGN_ENVELOPE_free
frees
.Fa signed_envelope .
.Pp
.Fn PKCS7_DIGEST_new
allocates and initializes an empty
.Vt PKCS7_DIGEST
object, representing an ASN.1
.Vt DigestedData
structure defined in RFC 2315 section 12.
It can be used inside
.Vt PKCS7
objects and holds any kind of content together with a message digest
for checking its integrity and information about the algorithm used.
.Fn PKCS7_DIGEST_free
frees
.Fa digested .
.Pp
.Fn PKCS7_ENCRYPT_new
allocates and initializes an empty
.Vt PKCS7_ENCRYPT
object, representing an ASN.1
.Vt EncryptedData
structure defined in RFC 2315 section 13.
It can be used inside
.Vt PKCS7
objects and holds any kind of encrypted content.
Keys are not included and need to be communicated separately.
.Fn PKCS7_ENCRYPT_free
frees
.Fa encrypted .
.Pp
.Fn PKCS7_ENC_CONTENT_new
allocates and initializes an empty
.Vt PKCS7_ENC_CONTENT
object, representing an ASN.1
.Vt EncryptedContentInfo
structure defined in RFC 2315 section 10.1.
It can be used inside
.Vt PKCS7_ENVELOPE ,
.Vt PKCS7_SIGN_ENVELOPE ,
and
.Vt PKCS7_ENCRYPT
objects and holds encrypted content together with information about
the encryption algorithm used.
.Fn PKCS7_ENC_CONTENT_free
frees
.Fa content .
.Pp
.Fn PKCS7_SIGNER_INFO_new
allocates and initializes an empty
.Vt PKCS7_SIGNER_INFO
object, representing an ASN.1
.Vt SignerInfo
structure defined in RFC 2315 section 9.2.
It can be used inside
.Vt PKCS7_SIGNED
and
.Vt PKCS7_SIGN_ENVELOPE
objects and holds a signature together with information about the
signer and the algorithms used.
.Fn PKCS7_SIGNER_INFO_free
frees
.Fa signer .
.Pp
.Fn PKCS7_RECIP_INFO_new
allocates and initializes an empty
.Vt PKCS7_RECIP_INFO
object, representing an ASN.1
.Vt RecipientInfo
structure defined in RFC 2315 section 10.2.
It can be used inside
.Vt PKCS7_ENVELOPE
and
.Vt PKCS7_SIGN_ENVELOPE
objects and holds a content-encryption key together with information
about the intended recipient and the key encryption algorithm used.
.Fn PKCS7_RECIP_INFO_free
frees
.Fa recip .
.Pp
.Fn PKCS7_ISSUER_AND_SERIAL_new
allocates and initializes an empty
.Vt PKCS7_ISSUER_AND_SERIAL
object, representing an ASN.1
.Vt IssuerAndSerialNumber
structure defined in RFC 2315 section 6.7.
It can be used inside
.Vt PKCS7_SIGNER_INFO
and
.Vt PKCS7_RECIP_INFO
objects and identifies a certificate by holding the distinguished
name of the certificate issuer and an issuer-specific certificate
serial number.
.Fn PKCS7_ISSUER_AND_SERIAL_free
frees
.Fa cert .
.Sh SEE ALSO
.Xr crypto 3 ,
.Xr d2i_PKCS7 3 ,
.Xr i2d_PKCS7_bio_stream 3 ,
.Xr PEM_read_PKCS7 3 ,
.Xr PEM_write_bio_PKCS7_stream 3 ,
.Xr PKCS7_decrypt 3 ,
.Xr PKCS7_encrypt 3 ,
.Xr PKCS7_ISSUER_AND_SERIAL_digest 3 ,
.Xr PKCS7_sign 3 ,
.Xr PKCS7_sign_add_signer 3 ,
.Xr PKCS7_verify 3 ,
.Xr SMIME_read_PKCS7 3 ,
.Xr SMIME_write_PKCS7 3
.Sh STANDARDS
RFC 2315: PKCS #7: Cryptographic Message Syntax Version 1.5
.Sh HISTORY
These functions first appeared in SSLeay 0.5.1
and have been available since
.Ox 2.4 .